K9 Rules:
Use MARP score system. It will reflect the fastest time as the best score, very simple! See Special Rules (Link) if necessary.
It´s required you post all your Stage Times in the description, also the Total Time.
Any of the default cars is allowed.

This game is a clone, however you do NOT need the PARENT ROMset [gtmr] if you get a recent [gtmrusa] ROMset only! It runs properly in 0.106 and 0.140.

PS.: There are 19 players that are able to play Round 8 in the match #927 (Battle for 6th (~24th)), for final ranking purposes. Feel free!

Using different MCU code for this game will cause playback issues. At some point, it was added (0.99u9, from the looks of it), but some sets will have a fake ROM. I guess MAME uses what is available, but it wasn't dumped until then.

Anyone playing it must ensure that they have the correct up-to-date ROMset. Some older versions prior to 0.99 are likely not to be able to be played back, unless you remove the MCU ROM from the zip, as the MCU wasn't dumped at that time.

I am pretty sure that using a recent (up-to-date) GTMRUSA romset would be enough to everyone play and playback on 0.106 and 0.140. Let me know if I am wrong. Waiting The_Pro and/or other submissions to confirm it.

About playbacking previous scores (ie Sawys' 0.89 ones), I think it's required an older romset, from that time, like mahlmiut said above.

Is there rank in this game? Using wolf106 or wolf140, once you get to level 8 the car doesn't autocenter anymore making it very hard to control. For example, tap right when going in a straight line and you'll normally move to the side and re-center. On level 8 you'll keep drifting.

It seems like this only happens if you reach level 8 on 1 credit, after failing and trying again the control returns to normal.

Why yes, I am posting too much in this thread. Some good news, if you can get past the insanity that is level 8, level 9 isn't too bad. Then autocenter goes back to normal in level 10, but quickly degenerates in level 11 and 12, though never as much as level 8-9. By level 10 it seems like hard cornering is tougher than it used to be but it's a difficult assertion to quantify, it might just be me. So anyway, it's do-able but you have to constantly adjust your direction.

The fact that autocenter goes back to normal and the back to broken tells me this might be an emulation issue rather than a feature but who knows.

I did many tests, and I think it's a Rank system, yes, on GTMRUSA version. Maybe the rank is also related to the "position" you got in the previous stage (and related to continues).
It's a bit affected by this rank, however, naturally, the stage 8 is the hardest in my opinion.
And like you said, it's do-able! Good luck to everyone!
PS.: INP playback correctly using 0.106.